Could cities soon be made of mushrooms?

Ah, mushrooms. Some are tasty, some are deadly and some will make you lick your hand and talk to the floor. But did you know that they could solve a ton of problems in the world’s cities? Some scientists believe that fungi could be used to clean rivers, as fuel in vehicles, and even to build homes.

As far-fetched as it sounds, the idea of building stuff out of mushrooms is pretty well established. The technology already exists and there’s an entire professional field – ‘myco-architecture’ – dedicated to it. In 2014, New York’s Museum of Modern Art commissioned a circular tower made of 10,000 bricks containing a mix of living mushrooms and corn stalk waste. Sure, the structure – named Hy-Fi – wasn’t habitable or particularly resilient (it’s since been taken down and composted), but it did show the potential of using fungi to build stuff.

Scientists working with this technology technically don’t use mushrooms exactly but things called mycelia, the root-like parts of a fungus. These can be grown into very complex, precise and strong structures, making it a really useful and adaptable building material.

Perhaps the strongest argument for mycelia construction is that, while normal building methods are a huge contributor to climate change (and waste a large amount of natural resources), fungi are totally renewable and much more eco-friendly. ‘The possibility of replacing plastics and other environmentally damaging materials and processes with something that is completely natural, and fully compostable, will be a game-changer for the way we make and consume things,’ says Eben Bayer, co-founder of mushroom tech firm Ecovative (yes, that’s a thing now).

Stuff made out of mycelia is also lightweight, fire-resistant and really easy to produce. ‘I’d like to envision a future where everything we need for a building project is made by fungi,’ says Maurizio Montalti, co-founder of Italian mycelia production firm Mogu. ‘Fungi have the potential to replace materials like plastic, stones and so on.’ From flooring and acoustic panels to bricks and art pieces, Mogu is already trying to propel myco-architecture into the mainstream.

Fungi could be the basis for a greener and more sustainable kind of interplanetary habitation

The firm is also part of a cross-European collaborative project called Fungal Architectures (FUNGAR), which is looking to test the limits of what can be achieved with the technology. Combining myco-architecture with ‘smart’ technology for the first time, FUNGAR is currently working on a building made out of fungi that reacts to light, temperature and air pollutants. In other words, it’s creating a building that is also a living, breathing structure.

Mycelia are so adaptable that NASA reckons they could one day be the ideal building material for houses on both the moon and Mars. Theoretically, a small and lightweight base of mycelia could be flown off to Mars, and provided with the right food and conditions to grow into a fully-fledged structure. Wild. The research is still in its earliest stages (after all, we haven’t even stepped foot on Mars yet), but fungi could one day be the basis for a greener and more sustainable kind of interplanetary habitation.

And that isn’t all. In a research field called ‘myco-filtration’, scientists have figured out how to use fungi to filter pollution out of rivers. These myco-filters were first pioneered in the 1980s by American mycologist, ‘shroom whizz’ and Fungi Perfecti founder Paul Stamets. Pretty nifty, seeing as they’re basically just huge sandbags filled with mycelia, wood chips and straw.

In the years since, myco-filters have been implemented all over the world, from the River Wandle in England to Lake Erie in upstate New York. And the benefits don’t stop there. ‘Research studies have shown that myco-filtration efficiently removes microbial pathogens such as E. coli from storm water, as well as heavy metals from contaminated drinking water sources,’ says Sanele Mnkandla, an eco-toxicologist at the University of the Free State in South Africa.

There’s plenty of potential for myco-filtration to be implemented on a city-wide scale as well. ‘Myco-filtration could also be implemented as a household wastewater treatment alternative in poorly resourced settings, thus ensuring sustainable sanitation,’ Mnkandla says. In other words, this cost-effective technology has the potential to solve all kinds of water pollution problems. Pretty great, eh?

Mushroom filtration tech has the potential to solve all kinds of water pollution problems

Researchers are working on ways to use mushrooms as a kind of biofuel, too. While this project is less developed than construction and water filtration, a team from the National University of Singapore reckons that one day biofuel from mushroom waste could be a direct substitute for gasoline. Imagine.

Before you get carried away, no, we are not talking about shoving mushrooms into a petrol tank and speeding off on your way. Producing fuel out of mushrooms is a complicated process – it involves using bacteria to break down biomass, fermenting it to produce something called biobutanol, which is one of the most exciting biofuels around.

‘Other biofuels like ethanol, biodiesel and biohydrogen require alterations in existing motor engines to function,’ says Dr Prachi Nawkarkar of the International Centre for Genetic Engineering and Biotechnology in New Delhi. ‘Biobutanol doesn’t require any alterations in the engine – the only bottleneck is its bulk availability to replace fossil fuels.’

So biobutanol isn’t just renewable: it could one day be a viable alternative to highly polluting, environmentally catastrophic fossil fuels. And on top of that, because the fuel is less volatile and explosive than petrol, it could also be easier and safer to transport.  

But the uses of mycelia stretch far beyond construction, filtration and fuel. The prospects for mushroom technology seem boundless: it could even be used to grow clothing, healthcare products, food packaging and superfoods. ‘Mycelia are kind of like an alien technology that we found in the forest,’ says Bayer. ‘It’s capable of so much, and we’re only just starting to understand its real potential.’

Now read about how our cities’ lost rivers are being revived.

Plus: here are 21 amazing things cities are doing to fight the climate crisis.